Accelerated Development of Salivary Glands of Early Postnatal Rats Following Isoproterenol.

Abstract

Chronic administration of the sympathetic amine isoproterenol to early postnatal rats (1–4 days old at time of first injection) for selected periods results in marked increases in the size of the submaxillary and parotid glands, and to a less extent, in the size of the heart. The sublingual salivary gland is unaffected. Other organs are reduced in size, especially after 3 to 5 weeks, when a retardation in body size and weight also becomes pronounced. A clear effect on differentiation of the parotid and submaxillary gland has been observed with isoproterenol treatment. The effect is most marked in parotid, where acini develop much earlier than in the litter-mate controls and striated ducts earlier become more abundant. The effects of isoproterenol on differentiation are separable from the influence of the drug on cell size.